Solar cell side surface interconnects

ABSTRACT

Peripheral side surface interconnects for interconnecting solar cells are disclosed. The peripheral side surface interconnects include a layer of an electrically conductive adhesive overlying an insulating layer overlying a peripheral side edge of a solar cell and electrically interconnected to a busbar. Photovoltaic modules include adjacent solar cells comprising peripheral side surface interconnects interconnected by the electrically conductive adhesive or by the electrically conductive adhesive and an interconnection element. An interconnection element can be a solder paste or a solder containing electrically conductive ribbon. Methods of forming solar cell peripheral side surface interconnects include applying an insulating layer to a side surface of a solar cell, depositing a busbar in proximity to the insulated side surface of the solar cell, depositing an electrically conductive adhesive over at least a portion of the busbar and over at least a portion of the insulating layer. Photovoltaic modules can be formed by interconnecting adjacent solar cells using a peripheral side surface interconnect.

This application is a continuation-in-part of U.S. application Ser. No.16/421,196 filed on May 23, 2019, which issued as U.S. Pat. No.10,622,502, which is incorporated by reference in its entirety.

FIELD

The present invention relates to solar cell interconnects. The solarcell interconnects facilitate the ability of adjacent solar cells to beinterconnected in a side-by-side configuration.

BACKGROUND

Adjacent solar cells can be interconnected using a solder-coated copperribbon to interconnect busbars on a frontside surface of a first solarcell to busbars on a backside surface of a second subcell. Suchinterconnects leave a gap between adjacent solar cells from about 1 mmto about 2 mm. The ribbons are typically soldered to the busbars therebypotentially exposing the surface of the solar cell to excessivetemperatures.

Reducing the gap between adjacent solar cells in a photovoltaic modulecan provide increased photovoltaic module power output and efficiencyand minimizing the exposure of the solar cells to high temperaturesduring assembly of photovoltaic modules can improve the performance andlong-term reliability of the photovoltaic modules.

SUMMARY

According to the present invention, a solar cell comprises: a substrate,wherein the substrate comprises a surface and a first peripheral sidesurface; one or more busbar segments disposed on the surface and inproximity to the first peripheral side surface; an insulating layeroverlying at least a portion of the first peripheral side surface; andan electrically conductive adhesive overlying at least a portion of theinsulating layer and overlying at least a portion of each of the one ormore busbar segments.

According to the present invention, a photovoltaic module comprises: afirst solar cell according to the present invention comprising one ormore first frontside busbar segments and a first electrically conductiveadhesive; and a second solar cell according to the present inventioncomprising one or more second backside busbar segments and a secondelectrically conductive adhesive; wherein the first electricallyconductive adhesive and the second electrically conductive adhesive arebonded and electrically interconnect the one or more first frontsidebusbar segments to the one or more second backside busbar segments.

According to the present invention, a photovoltaic module comprises: afirst solar cell, wherein the first solar cell comprises a firstfrontside surface, a first backside surface, a first peripheral sidesurface, one or more frontside busbar segments disposed on the firstfrontside surface and in proximity to the first peripheral side surface,and a first insulating layer overlying the first peripheral sidesurface; a second solar cell, wherein the second solar cell comprises asecond frontside surface, a second backside surface, a second peripheralside surface, one or more backside busbar segments disposed on thesecond backside surface and in proximity to the second peripheral sidesurface, and a second insulating layer overlying the second peripheralside surface; and an electrically conductive adhesive disposed on thefirst insulating layer and on the second insulating layer and overlyingat least a portion of the one or more first frontside busbar segmentsand overlying at least a portion of the one or more backside busbarsegments.

According to the present invention, a photovoltaic system comprises twoor more photovoltaic modules according to the present invention.

According to the present invention, a method of fabricating a solar cellinterconnect, comprises: depositing an insulating layer overlying aperipheral side surface of a solar cell; and depositing an electricallyconductive adhesive overlying at least a portion of the insulating layerand overlying at least a portion of each of one or more busbar segmentsto provide a solar cell interconnect.

According to the present invention, a solar cell comprises aninterconnect fabricated using a method according to the presentinvention.

According to the present invention, a method of interconnecting solarcells comprises: contacting a first electrically conductive adhesive ofa first solar cell according to the present invention to a secondelectrically conductive adhesive of a second solar cell according to thepresent invention; and bonding the first electrically conductiveadhesive to the second electrically conductive adhesive to interconnectthe first solar cell and the second solar cell.

According to the present invention, solar cells are interconnected usinga method according to the present invention.

According to the present invention, a photovoltaic module comprisessolar cells according to the present invention.

According to the present invention, a power system comprises a pluralityof photovoltaic modules according to the present invention.

According to the present invention, solar cell comprises: a substratecomprising a frontside surface, a backside surface, a first peripheralside surface, and a second peripheral side surface; a side surfaceinsulating layer overlying the first peripheral side surface; a backsideinsulating layer overlying a portion of the backside surface inproximity to the first peripheral side surface; one or more frontsidebusbar segments overlying the backside insulating layer; and a pluralityof frontside gridlines disposed on the frontside surface andinterconnected to the one or more frontside busbar segments.

According to the present invention, methods of fabricating a solar cellinterconnect comprise applying an insulating layer to a peripheral sidesurface of a solar cell; and extending gridlines on a frontside surfaceof the solar cell over the insulating layer and onto one or more busbarsegments on a backside surface of the solar cell.

BRIEF DESCRIPTION OF THE DRAWINGS

Those skilled in the art will understand that the drawings describedherein are for illustration purposes only. The drawings are not intendedto limit the scope of the present disclosure.

FIGS. 1A and 1B show the frontside (1A) and backside (1B) surfaces of alarge area solar cell, which can be cut longitudinally to provide four(4) small area solar cells of equal size.

FIGS. 2A-2C show views of a solar cell.

FIG. 3A shows a cross-sectional view of an example of a solar cellinterconnect provided by the present disclosure.

FIG. 3B shows a top view of an example of a solar cell side surfaceinterconnect provided by the present disclosure.

FIG. 3C shows a side view of an example of a solar cell side surfaceinterconnect provided by the present disclosure.

FIG. 3D shows a perspective view of an example of a solar cell sidesurface interconnect provided by the present disclosure.

FIG. 4 shows a cross-sectional view of an example of a solar cell havingtwo side surface interconnects provided by the present disclosure.

FIG. 5 shows a cross-sectional view of two solar cells interconnected bya side surface interconnect provided by the present disclosure.

FIG. 6 shows a cross-sectional view of three solar cells interconnectedby side surface interconnects provided by the present disclosure.

FIGS. 7A-7B show top and side views of an example of a solar cell.

FIGS. 8A-8B show top and side views of an example of a solar cell.

FIGS. 9A-9D show views of an example of a side surface interconnectprovided by the present disclosure.

FIGS. 10A-10B show views of an example of a side surface interconnectwith elastomer elements disposed on a peripheral side surface adjoiningelectrically conductive adhesive provided by the present disclosure.

FIG. 11 shows a cross-sectional view of two solar cells interconnectedby a side surface interconnect provided by the present disclosure andincluding a mechanical support element.

FIG. 12A shows a side view of a portion of a solar cell comprising aperipheral side surface interconnect with an interconnection elementbonded to an electrically conductive adhesive.

FIG. 12B shows a side view of a portion of a photovoltaic modulecomprising two solar cells interconnected by a peripheral side surfaceinterconnect comprising an interconnection element between twoelectrically conductive adhesive layers.

FIG. 13 shows a perspective view of two solar cells, with a first solarcell having a frontside busbar and frontside gridlines, and a secondsolar cell having a backside busbar and backside gridlines.

FIG. 14 shows the solar cells shown in FIG. 13 with an electricallyconductive adhesive deposited on at least a portion of the busbar and atleast a portion of the peripheral side surface of each of the two solarcells.

FIGS. 15A-15D show side views of examples of solar cells interconnectedusing side surface interconnects provided by the present disclosure. Theadjacent solar cells can be interconnected using an interconnectionelement such as, for example, a solder paste (FIG. 15A), a solder-coatedribbon (FIG. 15B), a solder-coated ribbon having convex outer surface(FIG. 15C), or a solder-coated ribbon having textured outer surfaces(FIG. 15D).

FIGS. 16A-16D show side views of solar cells interconnected using anelectrically conductive elastomer (FIG. 16A) or an electricallyconductive elastomeric element (FIGS. 16B-16D).

FIGS. 17A-17B show a cross-sectional view (FIG. 17A) and a side view(FIG. 17B) of a side surface interconnect in which the frontsidegridlines extend over the side surface.

FIG. 18 shows a cross-sectional view of an example of two solar cellsinterconnected by backside interconnect provided by the presentdisclosure.

FIG. 19 shows an example of a stack of solar cells used in depositing aninsulating layer such as a dielectric layer on the peripheral sidesurfaces of the solar cells.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawingsthat show, by way of illustration, specific details and embodiments inwhich the invention may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice thepresent invention. Other embodiments may be utilized, and structural,logical, and electrical changes may be made without departing from thescope of the invention. The various embodiments disclosed herein are notnecessarily mutually exclusive, as some disclosed embodiments may becombined with one or more other disclosed embodiments to form newembodiments. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope of the embodiments of thepresent invention is defined only by the appended claims, along with thefull scope of equivalents to which such claims are entitled.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

“Interconnect,” “interconnected,” and “interconnecting” refers toelectrical interconnection.

“Frontside surface” as in the frontside surface of a solar cell refersto the surface of the solar cell facing incident radiation.

“Backside surface” as in the backside surface of a solar cell refers tothe surface of the solar cell facing away from incident radiation.

“Peripheral side surface” as in the peripheral side surface of a solarcell refers to the outer side surfaces of a solar cell. The peripheralside surfaces extend from an edge of the frontside surface to arespective edge of the backside surface of a solar cell. FIG. 2B showsperipheral side surfaces 205 a, 205 c. and 205 d. In FIG. 2C, peripheralside surface 205 d is bounded by frontside surface 201, peripheral sidesurface 205 a, backside surface 206 and peripheral side surface 205 c.FIG. 2C shows a side-on view of peripheral side surface 205 a, which isbounded by front surface 201, peripheral side surface 205 b, backsidesurface 206, and peripheral side surface 205 d. The solar cell shown inFIGS. 2A-2C has four peripheral side surfaces. A solar cell can haveother shapes which can have a different number of peripheral sidesurfaces such as, for example, three or six peripheral side surfaces.

“Respective” as in respective busbars refers to interconnected busbars.

“Commensurate” means in alignment with and having similar dimensions.

“Overlying” means over. For example, a second layer that overlies afirst layer can lie adjacent or adjoin the first layer, or there can bean intervening material and/or structure between the first layer and thesecond layer. Overlying encompasses the term “against.”

“Adjacent” means against, on, or contacting without any interveningmaterial or structure.

“In proximity to” means near, a short distance away from, or close. Afeature that is in proximity to an edge can be near, a short distanceaway from, close to the edge; or can be at the edge.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of 1 and the recited maximum valueof 10, that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10.

The use of small-area solar cells can increase the power output and theefficiency of a photovoltaic system. A typical large-area solar cell canhave dimensions, for example, of about 156 mm×156 mm. Small-area solarcells can have an area that is, for example, less than 25%, 20%, or 15%the area of a large-area solar cell. Because the gridlines are shorter,the series resistance is reduced, and the busbars can be situated inproximity to a peripheral side edge of the solar cell. For example,because power loss due to series resistance (R) is related asP_(loss)=I²R the power loss can be significantly reduced and the fillfactor (F) and efficiency improves with small-area solar cells. Thus,for example, by reducing the area of a solar cell by 50% the power lossdue to the cell resistance can be reduced by 25%.

FIGS. 1A and 1B show a frontside (1A) and a backside (1B) of a largearea solar cell 100 including frontside busbars 101, frontside gridlines102, backside busbars 103, and backside contact 104. Large area solarcells are manufactured in high volume and are cost-effective to produce.Small-area solar cells can be fabricated, for example, by laser cuttinga large-area solar cell into four (4) or more small-area solar cells.Other sizes of small area solar cells can be cut from large area solarcells. For example, a large area solar cell having three busbars on thefrontside surface and can be cut into six small area solar cells. Smallarea solar cells can be cut from a large area solar cell can havedimensions, for example, of 156 mm×39 mm or of 156 mm×26 mm A small areasolar cell can have a surface area, for example, from 500 mm² to 10,000mm², from 2,000 mm² to 8,000 mm², from 3,000 mm² to 7,000 mm², or from4,000 mm² to 6,000 mm². To provide small area solar cells, a large areasolar cell can be cut in the middle of the busbars such that each of thesmall area solar cells has busbars at two peripheral side edges.

Adjacent small-area solar cells can be interconnected using conductiveribbon. For a conductive ribbon interconnect, a certain distance isrequired between adjacent solar cells to maintain electrical isolationbetween opposing peripheral side surfaces. The distance between theopposing peripheral side surfaces of adjacent solar cells can be, forexample, from 1 mm to 2 mm. Alternatively, in a shingled solar cellconfiguration a backside busbar of an overlying solar cell is directlyinterconnected to a frontside busbar of an underlying solar cellresulting in the interconnected solar cells having a non-planarconfiguration. As a result, for shingled solar cells there is ashadowing loss due to the extension of the overlying photovoltaic moduleabove the surface of the underlying solar cell. Thus, in bothconfigurations the active cell area per photovoltaic module area isreduced to various degrees by the interconnects. When multiplied overmultiple small-area solar cells used to form a photovoltaic module, thereduction in power per surface area can be significant.

Thus, to employ small-area solar cells to advantage, improvedinterconnects are desired.

The active area of a photovoltaic module can be increased by minimizingthe separation between the opposing peripheral side surfaces ofadjacent, interconnected solar cells. Solar cell interconnects providedby the present disclosure can be used to increase the active solar cellarea and thereby increase the power output and efficiency ofphotovoltaic power modules formed using small-area solar cells.

Solar cell interconnects provided by the present disclosure includeperipheral side surface interconnects and backside interconnects.

A peripheral side surface solar cell interconnect provided by thepresent disclosure can include a first electrically conductive adhesiveoverlying a peripheral side surface of a first solar cell andinterconnected to a busbar, a second electrically conductive adhesiveoverlying a peripheral side surface of a second solar cell andinterconnected to a busbar, and an interconnection elementinterconnecting the first and second electrically conductive adhesives.

A peripheral side surface solar cell interconnect provided by thepresent disclosure can include an electrically conductive adhesiveinterconnecting a busbar on the surface of a first solar cell to asecond busbar on a second solar cell.

A backside solar cell interconnect provided by the present disclosurecan include a configuration in which a frontside busbar is disposed onthe backside surface of a solar cell and the frontside gridlines extendover the peripheral side surface and interconnect to the frontsidebusbar overlying the backside surface. The frontside busbar of a firstsolar cell can be interconnected to a backside surface of a second solarcell by

Solar cell interconnects provided by the present disclosure can be usedwith a solar cell having any suitable dimensions and in particular smallarea solar cells. For example, solar cell interconnects provided by thepresent disclosure can be used to interconnect small area solar cellhaving surface areas from 500 mm² to 10,000 mm². Solar cellinterconnects provided by the present disclosure can be used tointerconnect solar cells having surface areas less than that of a largearea solar cell. For example, a solar cell interconnect provided by thepresent disclosure can be used to interconnect solar cells having asurface area from 500 mm² to 10,000 mm², from 1,000 mm² to 8,000 mm²,from 2,000 mm² to 7,000 mm², or from 3,000 mm² to 7,000 mm². A solarcell interconnect provided by the present disclosure can be used tointerconnect solar cells having a surface area less than 10,000 mm²,less than 8,000 mm², less than 6,000 mm², less than 4,000 mm², or lessthan 2,000 mm²

The solar cell interconnects provided by the present disclosure allowadjacent solar cells to be interconnected in a planar, side-by-sideconfiguration, such that when interconnected a peripheral side surfaceof one solar cell faces a peripheral side surface of an adjacent solarcell.

Side surface interconnects provided by the present disclosure can beused to interconnect any suitable solar cell. Examples of suitable solarcells include conventional Al-BSF (back surface field) solar cells,P-type PERC (passivated emitter rear contact) solar cells, N-PERT(passivated emitter rear totally diffused) solar cells, HIT(heterojunction with intrinsic thin layer) solar cells and TopCon(tunnel oxide passivated contact) solar cells

A solar cell can comprise gridlines and busbars formed using anysuitable material. For example, gridlines and busbars can be formed fromscreen-printed metallization pastes such as silver metallization pastes.Gridlines and busbars can have any suitable dimensions. The materialforming the busbars can be configured to facilitate the formation of alow resistivity and mechanically and environmentally robust interconnectto an electrically conductive adhesive.

Top and side views of a solar cell are shown in FIGS. 2A-2C.

FIG. 2A shows a view of the frontside surface 201 of a solar cell 200including a busbar comprising a plurality of busbar segments 203disposed in proximity to a first peripheral side edge 202 a of the solarcell. A second peripheral side edge 202 c is opposite the firstperipheral side edge 202 a and peripheral side edges 202 b and 202 d areorthogonal to side edges 202 a and 202 c. A plurality of grid lines 204are interconnected to frontside busbar segments 203.

FIG. 2B shows a side view of the solar cell shown in FIG. 2A. FIG. 2Bshows a frontside surface 201 of solar cell 200, a backside surface 206,a first peripheral side surface 205 a, a frontside busbar 203 disposedin proximity to frontside peripheral side edge 202 a and to peripheralside surface 205 a, and a plurality of frontside gridlines 204 disposedon the frontside surface 201 and interconnected to busbar 203.Peripheral side surface 205 a extends from backside surface 206 tofrontside peripheral side edge 202 a. Backside busbar 207 and aplurality of backside gridlines 208 are disposed on the backside surface206. Backside busbar 207 is in proximity to second peripheral sidesurface 205 c.

It will be appreciated that depending on the type of solar cell, abackside surface of a solar cell can include a busbar overlying aportion of the backside surface with gridlines interconnected to thebusbar, or the backside surface can include a conductor such as analuminum conductor covering the entire backside surface of a solar cell.When reference is made to a configuration having a backside busbar, itwill be understood that the configuration can equally apply to a solarcell having a backside conductor covering the entire backside surface.For example, an aluminum conductor covers the full back surface of aconventional Al back-surface field (BSF) solar cell; whereas p-type PERCsolar cells, and N-type PERT solar cells have gridlines interconnectedto a busbar on the backside surface of the solar cell.

FIG. 2C shows a view of peripheral side surface 205 a includingfrontside surface 201, backside surface 206, and frontside busbarincluding busbar segments 203. Peripheral side surface 205 a is boundedby peripheral side surface 205 b and peripheral side surface 205 d.

A side surface solar cell interconnect provided by the presentdisclosure can comprise an electrically conductive adhesive (ECA)interconnecting two solar cells and is referred to as a side surface ECAinterconnect. A side surface ECA interconnect does not include aninterconnection element other than the ECA.

A cross-sectional view of a portion of a solar cell comprising an ECAside surface interconnect provided by the present disclosure is shown inFIG. 3A. As shown in FIG. 3A, a solar cell 300 includes a substrate 301,a frontside surface 302, a backside surface 303, and a peripheral sidesurface 306. An insulating layer 304 overlies the peripheral sidesurface 306. A frontside busbar 305 is disposed on the frontside surface302 of the solar cell in proximity to peripheral side surface 306.Gridlines 308 are disposed on the frontside surface 302 and areinterconnected to frontside busbar 305. An electrically conductiveadhesive 307 overlies the insulating layer 304 and at least a portion ofthe frontside busbar 305.

A top view of the solar cell interconnect of FIG. 3A is shown in FIG.3B. FIG. 3B shows a view of the frontside of the solar cell includingfrontside surface 302, peripheral side surface 306, insulating layer 304overlying the peripheral side surface 306, and frontside busbarcomprising busbar segments 305 overlying frontside surface 302 and inproximity to peripheral side surface 306. Gridlines 308 are disposed onthe frontside surface 302 and are interconnected to busbar segment s305. Electrically conductive adhesive 307 overlies insulating layer 304and frontside busbar segments 305.

FIG. 3C shows a top view of the solar cell shown in FIGS. 3A and 3B withan electrically conductive adhesive 307 overlying the peripheral sidesurface 306 of the solar cell and overlying the frontside busbarsegments 305.

FIG. 3D shows a perspective composite view of the solar cell peripheralside surface interconnect shown in FIGS. 3A-3C. The elements areidentified as for FIGS. 3A-3C. FIG. 3D shows a cut-away portion of theelectrically conductive adhesive 307 overlying the insulating layer 304and a frontside busbar 305 in proximity to peripheral side surface 306.Gridlines 308 on frontside surface 302 are interconnected to busbar 305.

An electrically insulating layer isolates the peripheral side surface ofthe solar cell from the overlying electrically conductive adhesive. Theinterface between the insulating layer and the overlying ECA ismechanically and environmentally robust under typical solar cell useconditions.

An electrically insulating layer can comprise any suitable electricallyinsulating material, such as an organic or inorganic material. Examplesof suitable inorganic materials include polyimides, fluoropolymers,polyetheretherketones, and polyetherimides. Examples of suitableinorganic materials include oxides such as silicon oxide. An insulatingmaterial can comprise a dielectric material such as, for example,silicon nitride.

An electrically insulating layer can be applied to a peripheral sidesurface of a solar cell using any suitable method. For example, anelectrically insulating layer can be deposited using additivemanufacturing or by vapor deposition. For example, an inorganicinsulating layer can be deposited using metallo-organic chemical vapordeposition.

An insulating layer can comprise an organic material or an inorganicmaterial such as a dielectric material. An insulating layer can have athickness, for example, less than 200 nm, less than 100 nm, less than 50nm, or less than 20 nm. An insulating layer can have a thickness, forexample, from 10 nm to 100 nm, such as from 20 nm to 80 nm, or from 30nm to 60 nm.

An insulating layer can be a dielectric layer and can comprise, forexample, SiO₂, Si₃N₄, or Al₂O₃.

A dielectric layer can be deposited on the peripheral side surface of asolar cell using any suitable semiconductor deposition method such as,for example, plasma enhanced chemical vapor deposition, metal-organicchemical vapor deposition, or molecular beam epitaxy.

When a copper-containing electrically conductive adhesive is used, itcan be desirable that the insulating layer such as a dielectric layeralso serve to prevent diffusion of copper from the electricallyconductive adhesive into the active region of the solar cell. Elementssuch as phosphorus, gold, zinc, carbon, magnesium, indium, titanium,vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, niobium,molybdenum, tantalum and tungsten, can also diffuse into silicon andcreate recombination centers. Dielectric materials that can serve as adiffusion barrier include, for example, tungsten carbide (W₂C), titaniumsilicon nitride (TiSiN), ZrB₂, and amorphous MnSi_(x)O_(y). Thisdielectric layer can also passivate the edges of the silicon solarcells, thereby mitigating edge recombination effects. These diffusionbarriers can be electrically insulating and can be deposited by chemicalvapor deposition (CVD), which is a conformal coating process.Alternatively, other diffusion barriers such as tantalum nitride can beused/deposited using other semiconductor deposition methods such asphysical vapor deposition (PVD), which is not a conformal coatingprocess.

An electrically conductive adhesive can be ay suitable electricallyconductive adhesive used to fabricate solar cells. Electricallyconductive adhesives used for solar cell fabrication can comprise, forexample, an electrically conductive metal such as silver particles and athermosetting resin.

A suitable electrically conductive adhesive can have a binder comprisinga blocked polyisocyanate prepolymer as the primary or one of the primaryconstituents. Examples of suitable blocked isocyanates include alcoholblocked, phenol blocked, caprolactam blocked, pyrazol blocked,uretidione blocked, ketoximine blocked, amide blocked, imidazole blockedand malonate blocked-polyisocyanate. The blocked polyisocyanates can beunblocked with exposed to elevated temperatures.

A suitable electrically conductive adhesive can comprise a polyepoxideresin. Examples of suitable polyepoxide resins include bisphenol A typepolyepoxides, brominated bisphenol A type polyepoxides, bisphenol F typepolyepoxides, biphenyl type polyepoxides, novolac type polyepoxides, analicyclic polyepoxides, naphthalene type polyepoxides, ether series orpolyether series polyepoxides, oxirane ring-containing polybutadienes,silicone polyepoxide copolymers, and a combination of any of theforegoing.

An electrically conductive adhesive can comprise, for example, silverparticles, copper particles, or combinations thereof. An electricallyconductive adhesive can comprise, for example, from 60 wt % to 95 wt %of electrically conductive particles, where wt % is based on the weightof the electrically conductive adhesive. The electrically conductiveparticles can have an average particle diameter (d50), for example, from0.5 μm to 25 μm. The electrically conductive particles can also includemetal-coated particles such as metallic glass, or polymeric particlesthat are coated with an electrically conductive metal such as Au, Ag,Ni, and/or Cu.

When cured, an electrically conductive adhesive can have a curedthickness, for example, from 20 μm to 200 μm, from 20 μm to 150 μm, from20 μm to 100 μm, or from 20 μm to 60 μm. A cured electrically conductiveadhesive can have a thickness, for example, less than 200 μm, less than150 μm, less than 100 μm, or less than 50 μm.

An electrically conductive adhesive can comprise a curable resin. Thepolymer matrix can comprise one or more polymers such as (meth)acrylatecopolymers, polyesters, polyurethanes, polysiloxanes, polyethers,epoxy-amine-polyadducts, and combinations of any of the foregoing. Theresin systems can be thermally curable. For example, the resin systemcan be curable at a temperature from 110° C. to 230° C.

Elastomeric polymers such as ethylene copolymer-based (such as thosebased on ethylene vinyl acetate (EVA) can also be used, for example, inan alternating pattern with the electrically conductive adhesive (ECA)on the peripheral side surface of the solar cell.

The electrically conductive adhesive can comprise, for example, copper,a copper alloy, silver, a silver alloy, nickel, a nickel alloy, or acombination of any of the foregoing.

An electrically conductive adhesive can comprise Cu and/or Ag pastesthat can be cured at low temperatures such as from 120° C. to 230° C.,from 150° C. to 200° C., or from 160° C. to 180° C. The electricallyconductive adhesive can be curable at temperatures less than 250° C.,less than 200° C., less than 150° C. or less than 100° C. Electricallyconductive adhesives can be designed to provide an elastic interface toreduce mechanical stress between the solar cell interconnect and theinterconnected solar cell.

Examples of suitable electrically conductive adhesives include DD-1662K®series suitable for nozzle/syringe dispensing (commercially availablefrom Kyoto Elex Co., Ltd.).

Examples of suitable solder pastes include Loctite® HF 250DP suitablefor nozzle/syringe dispensing-type applications (commercially availablefrom Henkel).

An electrically conductive adhesive can comprise, for example, an epoxyresin, a polyimide resin acrylic resin, or a polycarbonate resin.

FIG. 4 shows a solar cell having two peripheral side surfaceinterconnects.

FIG. 4 shows a solar cell 400 having a substrate 401, a frontsidesurface 402, a backside surface 403, a first peripheral side surface404, and a second peripheral side surface 405. A first insulating layer406 overlies the first peripheral side surface 404, and a secondinsulating layer 407 overlies the second peripheral side surface 405. Afrontside busbar 408 is disposed on the frontside surface 402 inproximity to the first peripheral side surface 404 and a backside busbar409 is disposed on the backside surface 403 in proximity to the secondperipheral side surface 407. A first electrically conductive adhesive410 overlies the first insulating layer 406 and the frontside busbar408, and a second electrically conductive adhesive 411 overlies thesecond insulating layer 407 and the backside busbar 409.

In FIG. 4 an electrically conductive adhesive is shown on two peripheralside surfaces. A solar cell provided by the present disclosure can havean ECA side surface interconnect on one peripheral side surface, or ontwo or more peripheral side surfaces.

A photovoltaic module can comprise two or more solar cells comprising aperipheral side surface interconnect provided by the present disclosureand interconnecting the two or more solar cells.

Photovoltaic modules comprising two solar cells interconnected using aperipheral side surface interconnect is shown in FIG. 5 and in FIG. 6.

FIG. 5 shows a first solar cell 501 and a second solar cell 511interconnected through electrically conductive adhesive 507. First solarcell 501 includes a frontside surface 502, a backside surface 503, and aperipheral side surface 504 with overlying insulating layer 505.Frontside busbar 506 overlies frontside surface 502 in proximity toperipheral side surface 504. Second solar cell 511 includes a frontsidesurface 512, a backside surface 513, and a peripheral side surface 514with overlying insulating layer 515. Backside busbar 516 overliesbackside surface 513 in proximity to peripheral side surface 514. Thefrontside gridlines 509 on the frontside surface 502 of the first solarcell 501 are interconnected to frontside busbar 506. Backside conductoror gridlines 519 on the backside surface 513 of the second solar cell511 are interconnected to backside busbar 516. Electrically conductiveadhesive 507 interconnects the first solar cell 501 to the second solarcell 511 via frontside busbar 506, electrically conductive adhesive 507,and backside busbar 516. Electrically conductive adhesive 507 can beformed by bonding the electrically conductive adhesive 507 a/507 bbetween the two solar cells.

A photovoltaic module can comprise two or more solar cellsinterconnected by a peripheral side surface interconnect provided by thepresent disclosure. FIG. 6 shows an example where three solar cells areinterconnected.

FIG. 6 shows three solar cells, solar cells 601, 602, and 603interconnected with an ECA peripheral side surface interconnect providedby the present disclosure. As shown in FIG. 6, a frontside busbar 603 offirst solar cell 601 is interconnected to backside busbar 604 of secondsolar cell 602 through ECA 607, and frontside busbar 605 of second solarcell 602 is interconnected to backside busbar 606 of third solar cell603 through ECA 608. ECA 607 is insulated from first solar cell 601 byinsulating layer 609 and from second solar cell 602 by insulating layer610. ECA 608 is insulated from second solar cell 602 by insulating layer611 and from third solar cell 603 by insulating layer 612.

A busbar can comprise one or more busbar segments. A busbar can comprisea segmented busbar. A busbar can comprise a stripe of conductivematerial disposed in proximity to a peripheral side edge of a solarcell, such as at a peripheral side edge of a solar cell. A busbar can bea segmented busbar and can comprise two or more areas of conductivematerial disposed in proximity to a peripheral side edge of a solarcell, such as at a peripheral side edge of a solar cell. A busbar cancomprise an electrically conductive material or layer of conductivematerial such as an aluminum-containing layer that covers substantiallythe entire surface of a solar cell.

A frontside busbar and/or backside busbar of a solar cell can bedisposed in proximity to a peripheral side surface and can extend theentire length of the solar cell surface or a substantial length of thesolar cell surface in proximity to the peripheral side surface. Bysubstantially the entire length of the solar cell surface means that abusbar need not end against an orthogonal side edge but that there canbe some space between the busbar and the orthogonal side edge. Top andside views of a solar cell having a single busbar are shown in FIGS. 7Aand 7B respectively. FIGS. 7A and 7B include solar cell surface 701 anda single busbar 702 in proximity to peripheral side surface 703. Singlebusbar 702 extends substantially the entire length of the periphery ofthe solar cell between peripheral side surfaces 704 and 705. As shown inFIGS. 7A and 7B there can be a small gap between the orthogonalperipheral side edges 704/705 and the busbar 702.

A segmented busbar can include two or more busbar segments. Each of thetwo or more busbar segments can be disposed on a first portion of solarcell surface in proximity to a peripheral side surface. A second portionof the surface is between adjacent busbars. This is shown in FIGS. 8Aand 8B, which include four busbar segments 802 disposed on a firstportion of solar cell surface 801 in proximity to peripheral sidesurface 803. A second portion 804 of solar cell surface 801 is betweeneach adjacent busbar segment 802. For example, FIGS. 8A and 8B showbusbar segment 802 overlying first portions of surface 801 with secondportions 804 between adjacent busbar segments 802.

In solar cell interconnects provided by the present disclosure, theelectrically conductive adhesive can span substantially the entirelength of the peripheral side surface of a solar cell.

The electrically conductive adhesive can overlie substantially theentire length of the peripheral side surface of a solar cell and overliea substantial portion of a single busbar segment or busbar segments oroverlie only certain portions of a busbar or busbar segments. Theseembodiments are illustrated in FIGS. 3A and 3B. FIG. 3A shows theelectrically conductive adhesive 307 overlying substantially the entireperipheral side surface 306 and the entire single busbar segment 305.FIG. 3B shows electrically conductive adhesive 307 overlyingsubstantially the entire peripheral side surface 306 and multiple busbarsegments 305.

In embodiments comprising two or more busbar segments the electricallyconductive adhesive can overly a commensurate portion of the peripheralside surface.

FIGS. 9A and 9B show top and side views, respectively, of a solar cellhaving four busbar segments 902 disposed on a surface 901 of a solarcell in proximity to peripheral side surface 903. The multiple busbars902 are disposed on a first portion of surface 901 and are separated bya second portion of surface 905. An insulating layer 906 overliesperipheral side surface 903. Electrically conductive adhesive 907overlies a first portion of insulating layer 906 and adjacent firstportions of insulating layer 906 and are separated by a second portion908 of insulating layer 906 that does not contain an overlyingelectrically conductive adhesive. The first portions of the insulatinglayer are commensurate with respective busbar segments. Electricallyconductive adhesive 907 overlies each of the multiple busbar segments902. The first portion of surface 901 comprising busbar segments 902 arecommensurate with first portions of insulating layer 906 with overlyingelectrically conductive adhesive 907. Second portions 905 of surface 901without a busbar segment and second portions 908 of insulating layer 906without an overlying electrically conductive adhesive 907 isolateadjacent electrically conductive interconnects.

FIG. 9C shows a perspective view of the solar cells shown in FIGS. 9Aand 9B.

FIG. 9D show a perspective view of a peripheral side surface of a solarcell 900 having gridlines 901 interconnected to busbar segments 902disposed on frontside surface 903. Busbar segments 902 are at the edgeof peripheral side surface 906 and an insulating layer 907 covers theperipheral side surface 906.

FIG. 9E shows a perspective view of the peripheral side surface of asolar cell as shown in FIG. 9D further comprising an electricallyconductive adhesive overlying portions of the insulating layer 907commensurate with busbar segments 902 and independently overlying eachof the busbar segments 902.

A busbar can have, for example, a width from 0.1 mm to 1.3 mm, such asfrom 0.5 mm to 1 mm, or can be substantially the length of the solarcell.

Adjacent busbar segment can be separated by a distance, for example,from 10 μm to 3,000 μm, such as from 100 μm to 2,500 μm, or from 500 μmto 2,000 μm.

A frontside surface of a small area solar cell can include a busbar and,in some cases, the frontside surface does not include a busbar. Smallareas solar cells can be cut from a large area solar cell such that thegridlines extend to peripheral edges of the small area solar cell. Inthese embodiments, the electrically conductive adhesive overlies theperipheral side surface of the solar cell and overlies all of thegridlines or can overlie groups of gridlines.

Solar cell interconnects provided by the present disclosure can compriseone or more elastomeric elements disposed on the insulating layer. Anelastomeric element can be included to reduce shear stress on the solarcell interconnect and thereby reduce plastic deformation and increasethe tensile strength of the electrically conductive adhesiveinterconnect. A photovoltaic module can be subjected to shear forcesduring assembly and/or during use resulting from differential thermalexpansion coefficients of the various materials forming a photovoltaicmodule including the solar cell interconnects provided by the presentdisclosure.

FIGS. 10A-10C show an example of a solar cell interconnect comprisingelastomeric elements.

FIGS. 10A and 10B show top and side views, respectively, of a solar cellperipheral side surface interconnect comprising elastomeric elementsprovided by the present disclosure.

FIGS. 10A and 10B show solar cell surface 1001, busbar segments 1002disposed on surface 1001 in proximity to peripheral side surface 1003.Insulating layer 1004 overlies the peripheral side surface 1003.Electrically conductive adhesive 1007 overlies a portion of theinsulating layer 1004 and overlies each of the busbar segments 1002. Anelastomeric element 1010 overlies each second portion of the insulatinglayer 1004 including the portions between side edges 1005 and 1006. Anelastomeric element 1010 can overlie each of the second portions ofinsulating layer 1004, some of the second portions, only the secondportions between the side edges 1005/1006, or only between the nearestelectrically conductive adhesive overlying the first portions ofinsulating layer 1004.

An elastomeric element can have a thickness that is approximately thesame as the thickness of the electrically conductive adhesive or lessthan the thickness of the electrically conductive adhesive.

An elastomeric element can have a thermal expansion coefficient that is2×10⁻⁴ m/m° C.

An elastomeric element can comprise a thermoplastic elastomer or athermoset elastomer.

Examples of suitable thermoplastic elastomers include, for example,polyamide and ethylene-vinyl acetate.

Examples of suitable thermoset elastomers include silicone rubber.

A suitable elastomer can be formulated to have a thermal expansioncoefficient, for example, from 5×10⁻⁵ m/m° C. to 4×10⁻⁴ m/m° C.

A suitable elastomer can have glass transition temperature, for example,less than −40° C., less than −20° C., or less than −15° C.

A suitable elastomer can have modulus, for example, from 0.5 MPa to 55MPa.

A suitable elastomer can have a melt temperature greater, for example,than 100° C., greater than 200° C., or greater than 300° C.

A suitable elastomer can have a tensile strength, for example, from 1MPa to 60 MPa

A suitable elastomer can have a % elongation, for example, from 100% to4,500%, such as from 250% to 4,000%, or from 500% to 2,000%.

A suitable elastomer can comprise filler such as, for example, inorganicand/or organic filler, thermal stabilizers, UV stabilizers,antioxidants, leveling agents, and combinations of any of the foregoing.

An elastomeric element can comprise a cellular foam.

Elastomeric elements can be applied onto the second portions of theperipheral side surface either before or after the electricallyconductive adhesive is applied. The elastomeric elements can bedeposited using additive manufacturing such as by three-dimensionalprinting and/or by inkjet printing.

Photovoltaic modules provided by the present disclosure can be formed bycuring an electrically conductive adhesive deposited between opposingperipheral side surfaces of adjacent solar cells to interconnect theadjacent solar cells.

A photovoltaic module can be formed by bringing an electricallyconductive adhesive on a peripheral side surface of a first solar cellinto contact with an electrically conductive adhesive on a peripheralside surface of a second solar cell. The electrically conductiveadhesives can be brought together with slight pressure. When joined, theelectrically conductive adhesives can be merged with a back and forthmotion and/or ultrasonic energy can be applied to the joinedelectrically conductive adhesive to facilitate the ability of the twoelectrically conductive adhesives to merge.

The electrically conductive adhesives on the two solar cells can bebrought into contact before the electrically conductive adhesives whilethe electrically conductive adhesives are wet, such as before theelectrically conductive adhesives are dried and cured or before apartially dried film forms on the surface of the electrically conductiveadhesives.

After the electrically conductive adhesives on the peripheral sidesurfaces of the two solar cells has been brought into contact, theelectrically conductive adhesive can be dried, for example, by exposingthe electrically conductive adhesive to a temperature, for example, from125° C. to 175° C. for a duration, for example, from 2 minutes to 20minutes, such as from 145° C. to 155° C. for a duration, for example,from 5 minutes to 10 minutes. A suitable time and temperature can bedetermined by the electrically conductive adhesive formulation and theconditions necessary to drive off solvent and low molecular weightspecies from the electrically conductive adhesive.

After the electrically conductive adhesive has been dried, theelectrically conductive adhesive can be cured, for example, by exposingthe electrically conductive adhesive to a temperature from 150° C. to250° C. or from 20 minutes to 60 minutes, such as from 175° C. to 225°C. for from 30 minutes to 50 minutes. The temperature and duration ofthe curing exposure can depend on the electrically conductive adhesiveformulation and on the curing chemistry.

An electrically conductive adhesive can comprise a free radical curingchemistry. The free radicals can be generated, for example, by exposingan ECA comprising a free radical photoinitiator to actinic radiationsuch as ultraviolet radiation or the electrically conductive adhesivecan comprise chemical or thermal free radical initiators.

To provide additional mechanical support for a peripheral side surfacesolar cell interconnect provided by the present disclosure, an externalelastomeric element can be disposed on the frontside and/or backsidesurfaces of a peripheral side surface interconnect. An example is shownin FIG. 11. FIG. 11 shows a first solar cell 1101 having a frontsidebusbar 1102 on frontside surface 1103 and a second solar cell 1111having a backside busbar 1112 on backside surface 1113. Electricallyconductive adhesive 1105 interconnects the frontside busbar 1102 andbackside busbar 1112 and is insulated from the substrates by peripheralside surface insulators 1104/1114. A frontside elastomeric element 1106is disposed on the frontside surface of the electrically conductiveadhesive 1105 and a backside elastomeric element 1107 is disposed overthe backside surface of the electrically conductive adhesive 1105. Thefrontside and backside elastomeric elements 1106/1107 can extend thewidth of the peripheral side surface interconnect, a portion of theperipheral side surface interconnect, or portions of the peripheral sidesurface interconnect.

The external elastomers can improve the mechanical integrity of theperipheral side surface interconnect and can improve the environmentalreliability of the peripheral side surface interconnect by sealingand/or shielding the underlying electrically conductive adhesive fromenvironmental conditions such as water, moisture, abrasion, corrosivematerials, gases, and/or radiation including visible, infrared andultraviolet radiation.

Photovoltaic modules can be fabricated by interconnecting a first ECA ofa first solar cell to a second ECA on a second solar cell through aninterconnection element.

An interconnection element can be applied to a surface of an ECAinterconnect before the two solar cells are interconnected, during theprocess of bringing the two solar cells into close proximity, or afterthe two solar cells are brought into close proximity.

A solar cell interconnect provided by the present disclosure can havethe structure shown in FIG. 12A. As shown in FIG. 12A, a solar cell 12can include a substrate 1201, a frontside surface 1202, a backsidesurface 1203, a busbar 1205 and gridlines 1208 disposed on the frontside surface 1202, an insulating layer 1204 overlying peripheral sidesurface 1206, an ECA 1207 overlying at least a portion of insulatinglayer 1204 and a busbar 1205, and an interconnection element 1209overlying and interconnected to the ECA. The interconnection element canbe mechanically and electrically bonded to the ECA. For example, theinterconnection element can be held in place by the cured ECA.

A cross-sectional view of a photovoltaic module interconnected using aperipheral side surface interconnect having an interconnection elementis shown in FIG. 12B. As shown in FIG. 12B, a first solar cell 1201 isinterconnected to a second solar cell 1211 through peripheral sidesurface interconnect 1210. Solar cell 1201 includes a substrate 1202, afrontside busbar 1205 on the frontside surface 1203 and the busbar 1205is situated in proximity to peripheral side surface 1206. An insulatinglayer 1207 is disposed on at least a portion of the peripheral sidesurface 1206 of the first solar cell 1201. ECA 1208 overlies at least aportion of the insulating layer 1207 and the frontside busbar 1205. Thesecond solar cell 1211 includes a substrate 1212, a backside busbar 1215on the backside surface 1214 and is situated in proximity to peripheralside surface 1216. An insulating layer 1217 is disposed on at least aportion of the peripheral side surface 1216 of the second solar cell1211. ECA 1218 overlies at least a portion of insulating layer 1216 andbackside busbar 1215. Peripheral side surface interconnect 1210 includesan electrically conductive adhesive 1208 disposed on at least a portionof the frontside busbar 1205 and overlying at least a portion of thefirst insulating layer 1207; electrically conductive adhesive 1218disposed on at least a portion of the backside busbar 1215 and overlyingat least a portion of insulating layer 1217; and an interconnectionelement 1209. Interconnect 1210 electrically interconnects frontsidebusbar 1205 on the first solar cell 1201 to backside busbar 1215 on thesecond solar cell 1211.

As shown in FIG. 12B, an interconnection element 1209 electricallyinterconnects the electrically conductive adhesive 1208 on the firstsolar cell 1201 to the electrically conductive adhesive 1218 on thesecond solar cell 1211.

The interconnection element 1209 can be weldable such that theinterconnection element 1209 provides sufficient mechanical integrityand has a low electrical resistance. It can be desirable that theinterconnection element maintain the structural integrity of thephotovoltaic module when exposed to thermal stress under typical useconditions.

An interconnection element can comprise, for example, a solder paste ora solder-coated ribbon. An interconnection element can comprise, forexample, an electrically conductive elastomer or an electricallyconductive elastomeric element.

Frontside and backside gridlines (not shown) can be disposed on thefrontside and backside surface of the first and second solar cells1201/1211. The surface electrodes of a solar cell such as the frontsideand backside gridlines can be made of any suitable electricallyconductive material. The surface electrodes can be formed by printingsuch as by screen printing or ink-jet printing, conductive paste overthe solar cell surfaces. Examples of suitable paste materials includesilver paste, copper paste, glass pastes containing silver, gold paste,carbon paste, nickel paste, aluminum paste, transparent conductive oxide(TCO), such as indium tin oxide (ITO), and aluminum zinc oxide (AZO).

The gridlines and busbars of the solar cells may be in any suitablepattern, shape and dimension.

For example, in a wafer-based photovoltaic module, each solar cell maycomprise frontside gridlines and backside gridlines, wherein frontsidegridlines can comprise a plurality of parallel conductive lines and twoor more conductive frontside busbars perpendicular to and interconnectedto the conductive frontside gridlines, and wherein the backsidegridlines can comprise a layer of conductive paste and two or moreconductive backside busbar segments. The conductive frontside gridlinesand the conductive frontside busbar segments can be formed, for example,of silver and the backside gridlines can be formed of silver gridlinesor in case of a conventional Al-BSF solar cell a full-backside aluminumconductor paste is printed in intimate contact with the backside silverbusbar paste. Frontside gridlines, backside gridlines, and busbars aretypically fabricated from silver-containing metallization pastes. Thetype of metallization paste depends on the type of doped region beinginterconnected.

In general, for silicon solar cell metallization applications,thick-film pastes are used to form the frontside gridlines, frontsidebusbars, backside gridlines, and backside busbars. Thick-film pastes caninclude a suspension of conductive metal, glass frit, organic vehicles,and modifiers. Silver is the most common conductive filler used forfrontside paste. Glass frit is used to bind the functional/conductivephase to a silicon wafer after thermal treatment. The glass frit alsoetches through anti-reflective and passivation layers to provide ohmiccontact between the silver grid and the silicon surface of the solarcell. The organic vehicle can be an organic system that acts as arheological carrier to control flow and printability of the paste. Theorganic vehicle can comprise resins, solvents, and additives. Theattributes of the metallization paste, in particular the frontsidesilver paste, is important for achieving high efficiency solar cells.Therefore, the quality and performance of the silver metallization pasteaffects the economics of solar power systems. The screen-printingtechnology that is currently used for the majority of solar cells isbeing further developed for printing fine-line conductive grids toreduce silver consumption and thereby reduce cost, reduce shading andthereby increase the current density, and improve photovoltaic moduleperformance.

An interconnection element can comprise a solder-coated ribbon. Asolder-coated ribbon can have a thickness and width, for example, thatis less than the thickness of a solar cell being interconnected. Theedge of a solder-coated ribbon facing the incident solar radiation canhave a substantially flat surface or can have a cross-sectional profilethat enhances the ability of incident solar radiation to impinge uponthe active regions of the solar cell. For example, the front and backedges of the solder-coated ribbon can have a convex shape or can have betextured.

A solder-coated ribbon can comprise a ribbon of an electricallyconductive material such as Cu or Ag, with an exterior coating of asolder or solder alloy. A ribbon can have any suitable cross-sectionalshape such as rectangular, circular, or oval. The exterior surface ofthe ribbon facing incident solar radiation can be configured tofacilitate scattering of incident solar radiation onto active areas ofthe solar cell. For example, the exterior surface of a ribbon can beconvex and/or textured.

A solder coating can have a thickness, for example, from 0.5 μm to 70μm, such as from 10 μm to 50 μm.

The ribbon can be in the form of a thin sheet such as a foil.

Any suitable solder can be used. For example, a solder can comprise from30 wt % to 100 wt % tin, and one or more of lead, silver, bismuth, zinc,copper, or a combination of any of the foregoing, independently in anamount from 0 wt % to 50 wt % such as from 1 wt % to 40 wt %, where wt %is based on the total weight of the solder alloy.

Solar cell edge interconnects provided by the present disclosure can beused with any suitable solar cell.

Solar cells comprising a peripheral side surface interconnect providedby the present disclosure comprise a surface and an edge, a busbar inproximity to the edge, a dielectric layer overlying the edge, and anelectrically conductive adhesive overlying at least a portion of thedielectric layer and overlying at least a portion of the busbar.

A solar cell can comprise a wafer-based solar cell such as a c-Si or anmc-Si solar cell; a thin-film solar cell such as an a-Si, μc-Si, CdTe,copper indium selenide (CIS), or copper-indium-gallium selenide (CIGS)solar cells, light absorbing dyes, or organic semiconductor-based solarcells

A busbar can be disposed in proximity to a peripheral edge of the solarcell or, for example, within less than 25 μm, less than 50 μm, less than100 μm, or less than 200 μm from a peripheral edge of a solar cell. Abusbar can be located near or at a peripheral edge of the solar cell tomaximize the active area of the solar cell. A busbar can comprise anysuitable material such as a conductive Ag thick-film. A busbar can beinterconnected to a plurality of grid lines.

A peripheral side surface a solar cell can comprise an insulating layersuch as a dielectric layer. An insulating layer can comprise adielectric material such as, for example, SiO₂, Si₃N₄, or Al₂O₃. Apurpose of the insulating layer is to electrically insulate a peripheralside surface of the solar cell from the electrically conductive adhesiveforming the side surface interconnect.

Methods provided by the present disclosure include methods offabricating a solar cell side surface interconnect and methods ofinterconnecting solar cells using a side surface interconnect to providephotovoltaic modules.

Methods of fabricating a solar cell side surface interconnect providedby the present disclosure can comprise depositing an insulating layersuch as a dielectric layer overlying a peripheral side surface of asolar cell and depositing an electrically conductive adhesive overlyingat least a portion of the insulating layer and overlying at least aportion of the busbar to provide a solar cell side surface interconnect.

Small-area solar cells such as solar cells having areas, for example,from about 500 mm² to 10,000 mm² such as from about 2,000 mm² to 8,000mm², can be cut from larger area solar cells by laser grooving followedby mechanical separation. For example, a large-area solar cell can beseparated into stripes having a width, for example, from about 15 mm toabout 60 mm, and a length, for example, from 100 mm to 200 mm.

The large area solar cells include busbars and gridlines. After lasercutting the large area solar cells into small area solar cells, thesmall area solar cells can have busbars and gridlines or can only haveonly gridlines.

An insulating layer such as a dielectric layer can be deposited on aperipheral side surface of a solar cell using any suitable semiconductordeposition method such as, for example, chemical vapor deposition,molecular beam epitaxy, physical vapor deposition, or remote plasmaenhanced chemical vapor deposition.

To deposit the insulating layer on an edge of solar cell, multiple solarcells can be stacked, and an insulating layer deposited on exposedperipheral side surfaces of the stacked solar cells. In this way, aninsulating layer can be simultaneously applied to multiple solar cells.An insulating layer can be applied to a first peripheral surface and toa second peripheral surface of a solar cell, where the second peripheralsurface is opposite the first peripheral surface. An insulating layercan be applied to peripheral solar cell surfaces that will be inproximity to the busbars. An insulating layer can be deposited to coverthe edge of each of the solar cells in the stack. A dielectric layer canbe applied to all four edges of a solar cell. An insulating layer can beapplied to one or more peripheral side surfaces of a small area solarcell.

FIG. 19 shows a stack of solar cells including peripheral side surfaces1901 and 1902.

After depositing an insulating layer on opposing peripheral sidesurfaces of a large area solar cell, individual large area solar cellscan be separated from the stack and cut into small area solar cells. Anelectrically conductive adhesive can then be applied to the peripheralside surfaces containing an insulating layer and to the busbars and/orgridlines of the small area solar cell. For example, an electricallyconductive adhesive (ECA) can be applied to a first peripheral side edgeand corresponding frontside busbar and/or to a second peripheral sideedge and corresponding backside busbar of the solar cell using anysuitable ECA materials and application methods.

FIG. 13 shows a configuration of busbars and gridlines on two solarcells. Gridlines 1301 are interconnected to respective busbar segments1302 on the frontside of a first solar cell 1303, and gridlines 1311 areinterconnected to busbar segments 1312 of the backside of a second solarcell 1305. The peripheral side surfaces of both solar cells are coatedwith an insulating layer such as a dielectric layer 1306/1316.

After the busbars and gridlines are formed, an electrically conductiveadhesive can be applied to the surface of the insulating layer or to aportion of the surface of the insulating layer and to the surface of abusbar or to a portion of the surface of a busbar. When cured, theelectrically conductive adhesive is electrically interconnected to thebusbar and is electrically insulated from the peripheral side surface ofthe solar cell by the insulating layer.

The electrically conductive adhesive can be applied to an insulatedperipheral side surface of a solar cell using, for example, additivemanufacturing such as by pulsed three-dimensional printing or byextrusion three-dimensional printing. The electrically conductiveadhesive can be applied to the insulated peripheral side surface of asolar cell using, for example, transfer printing. An electricallyconductive adhesive can cover the insulating layer or can be patternedto cover selected portions of the insulating layer. The electricallyconductive adhesive can be applied to cover the insulating layer, tocover a portion of the insulating layer, to contact the entire length ofa busbar, to contact a portion of the length of the busbar, or acombination of any of the foregoing.

After the electrically conductive adhesive is applied to the insulatedperipheral side surface of the solar cell, the electrically conductiveadhesive can be cured at a temperature, for example, from 150° C. to250° C., for a duration, for example, from 20 minutes to 60 minutes. Theheat can be applied, for example, by passing the solar cell through abelt oven. Before, curing, the electrically conductive adhesive can bedried, for example, by exposing the electrically conductive adhesive toa temperature, for example from 100° C. to 200° C. for a duration, forexample, from 5 minutes to 20 minutes.

FIG. 14 shows two solar cells having an electrically conductive adhesiveapplied to the busbars and to opposing peripheral side surfaces of therespective solar cells. FIG. 14 shows gridlines 1401 interconnected tobusbar segments 1402 on the frontside of the first solar cell 1403, andgridlines 1411 interconnected to busbar segments 1412 on the backside ofthe second solar cell 1413. An electrically conductive adhesive1408/1418 covers the busbar segments 1402/1412 and extends over theedges of the solar cells to partially cover the insulating layer1406/1416. Each of the solar cells shown in FIG. 14 includes fourbusbars. As shown in FIG. 14, the electrically conductive adhesive ispatterned to cover the portion of the insulating layer in proximity toand commensurate with a respective busbar segment. In certainembodiments, the ECA can extend the length of the peripheral sidesurfaces and/or cover the peripheral side surfaces of the solar cell.

After peripheral side surface interconnects are formed on the positiveand/or negative busbars of a solar cell, the solar cell can beinterconnected to another solar cell to form a photovoltaic module.

To form a photovoltaic module, peripheral side surface interconnects oftwo solar cells can be interconnected with an electrically conductiveadhesive or with an electrically conductive adhesive and aninterconnection element that has low resistivity and can providemechanical support for the interconnect. The electrically conductiveadhesive or the electrically conductive adhesive and the interconnectionelement, when cured, can maintain the structural integrity of the solarcell interconnect during use conditions.

Two or more solar cells can be interconnected by the peripheral sidesurface interconnects to form a photovoltaic module.

It is desirable that the interconnection element be thin so as tominimize the separation between adjacent solar cells in order to reducethe resistance of the interconnect and to increase the active area ofthe photovoltaic module per module area.

An interconnection element can have a width, for example, that is lessthan the thickness of the solar cells being interconnected. For example,an interconnection element can have a width less than 250 μm, less than225 μm, 200 μm, less than 175 μm, less than 150 μm, less than 125 μm,less than 100 μm, or less than 75 μm. An interconnection element canhave a thickness, for example, from 50 μm to 250 μm, from 75 μm to 225μm, from 100 μm to 200 μm, or from 125 μm to 175 μm.

An interconnection element can have a thickness that is less than thethickness of the solar cells being interconnected. For example, aninterconnection element can have a thickness less than 200 μm, less than175 μm, less than 150 μm, less than 125 μm, less than 100 μm, or lessthan 75 μm. An interconnection element can have a thickness, forexample, from 50 μm to 200 μm, from 75 μm to 175 μm, or from 100 μm to150 μm.

Two solar cells can be interconnected by bringing two opposing solarcell peripheral side surface interconnects into proximity andinterconnected using an interconnection element.

An interconnection element can comprise, for example, a solder paste ora solder-coated ribbon.

When a solder paste is used as the interconnection element, two edgeinterconnects can be brought into proximity and a solder paste can beapplied within the gap separating the opposing edge interconnects. Thesolder paste can be applied, for example, using additive manufacturingsuch as using three-dimensional printing.

Alternatively, a solder paste can be applied to the electricallyconductive adhesive on an edge of a solar cell and an edge interconnectof a second solar cell can be brought into contact with the electricallyconductive adhesive and subsequently cured to interconnect the two solarcells. The edge of the second solar cell may or may not have an appliedsolder paste before joining the edges of the two solar cells.

After the solder paste is applied and the solar cell edges arepositioned, the solder paste can be cured at a temperature, for example,from 150° C. to 400° C. such as from 200° C. to 240° C., to interconnectthe solar cells.

When a solder-coated ribbon is used as the interconnection element, thetwo edge interconnects can be brought into close proximity, and thesolder-coated ribbon can be placed within the gap between the twoopposing edge interconnects. The solder-coated ribbon can be press-fitinto the gap or otherwise inserted into the gap between the edgeinterconnects and the opposing peripheral side surface interconnects. Ifappropriate, the opposing peripheral side surface interconnects can bebrought closer together to adjust the separation and/or pressure of theperipheral side surface interconnects on the interconnection element tofacilitate the formation of an electrically and mechanically viableinterconnect.

Certain portions of the gap between opposing peripheral side surfaceinterconnects can comprise a component configured to enhance themechanical strength of the solar cell interconnect. For example, thecomponent need not be electrically conductive. The component can bethermally conductive and/or thermal dissipative. The component can berigid, elastomeric, or a combination thereof. The component can be, forexample, a thermoset, thermoplastic, metal, metal alloy, ceramic, orcomposite material. A component can be situated in between electricallyconductive regions of the module interconnect.

A non-electrically conductive elastomeric component can be printed onthe edge of the solar cell using, for example, three-dimensionalprinting, to form an alternating pattern between the conductive adhesiveon the first and second solar cells and the elastomeric component, whichcan be facing each other on both adjacent solar cells. The elastomericpolymer can be cross-linked during the electrically conductive adhesivecuring or can be subsequently printed and cross-linked during laminationof the photovoltaic module. Alternatively, an elastomeric polymerprinted between the electrically conductive adhesive patterns on theedges of the solar cells may not be necessary if the electricallyconductive adhesive such as ethylene vinyl acetate (EVA) front and backlaminating layers of the photovoltaic module fill the gaps between theelectrically conductive adhesive patterns on the edges of the adjacentsolar cells. In this case, the EVA may provide the necessary flexibleadhesive bond that relieves mechanical stresses between the solar cells.

After the interconnection element has been deposited or positionedbetween the opposing solar cell edge interconnects, the interconnect canbe heated to cause an electrically conductive bond such as a solder tothe electrically conductive adhesive to electrically interconnect twosolar cells to form a photovoltaic module. The solder paste, orsolder-coated ribbon can be bonded to the electrically conductiveadhesive, for example, bypassing the module pre-assembly through aradiation lamp heated or resistance heated oven.

The process can be used to simultaneously and/or sequentiallyinterconnect additional solar cells.

FIGS. 15A-15D show cross-sectional views of solar cells interconnectedusing peripheral side surface interconnects provided by the presentdisclosure. The cross-sectional views include a first solar cell 1501, afrontside busbar 1502, an insulating layer 1503, an electricallyconductive adhesive 1504, a second solar cell 1505, a backside busbar1506, an insulating layer 1507, an electrically conductive adhesive1508, and an interconnection element 1509. In FIG. 15A theinterconnection element is a solder paste, in FIG. 15B theinterconnection element is a solder-coated ribbon including a core 1510and solder 1511, in FIG. 15C the interconnection element is asolder-coated ribbon in which the upper surface is convex to enhancelight scattering and light trapping in the photovoltaic module, and inFIG. 15D the interconnection element is a solder-coated ribbon in whichthe upper surface is textured to enhance light scattering and opticaltrapping in the photovoltaic module.

An interconnection element used to interconnect two solar cell sidesurfaces can comprise an elastomeric interconnection element. Theelastomeric interconnection element can be configured to provideflexibility to the interconnect to accommodate mechanical stressgenerated at the interconnect during use conditions, such as generatedby thermal stress. An elastomeric interconnection element can be anelectrically conductive elastomer. The electrically conductive fillercan be dispersed homogenously or in homogeneously within the elastomericinterconnection element. For example, the electrically conductive fillercan be disposed on the outer surface of the elastomeric interconnectionelement.

The electrically conductive filler can be in any suitable form such asparticles, flakes, filaments, and/or wires. The electrically conductivefiller can comprise a suitable amount of a weldable material such as asolder alloy for bonding to the electrically conductive adhesive on theedges of the solar cell.

Any suitable elastomer or combination of elastomers can be used, whichcan be thermosets or thermoplastic elastomers.

An elastomeric interconnection element can have a core/shellconfiguration. For example, the interior of the interconnection elementcan be elastomeric, which is surrounded by a shell of an electricallyconductive material. The electrically conductive material can be, forexample, an electrically filled elastomer, or a thin electricallyconductive foil such as a solder-coated foil.

Exterior surfaces of an elastomeric interconnection element can haveexterior (top and bottom) surfaces comprising an environmentally inertmaterial configured to enhance the weatherability of the elastomericinterconnection element. For example, the outer surfaces of theelastomeric interconnection element can comprise a weatherable polymerwhich covers a shell of an electrically conductive material.

An elastomeric interconnection element can be formed or applied bymethods such as coextrusion and inserted between opposing solar celledges during assembly. An elastomeric interconnection element can beformed in place using coextrusion methods.

An elastomeric interconnection element can further comprise thermallyconductive filler. An elastomeric interconnection element can furthercomprise filler configured to enhance the mechanical robustness andstability of the interconnect, such as fiber including, for example,silica fiber, carbon fiber, metal fiber, and/or organic fiber.

FIGS. 16A-16D show cross-sectional views of examples of solar cellsinterconnected using elastomeric interconnection elements 1601. FIGS.16A-16D include first solar cell 1604 with busbar 1606 disposed onfrontside surface 1605, insulating layer 1608 disposed on peripheralside surface 1607, and ECA 1609 overlying at least a portion ofinsulating layer 1608 and busbar 1606. FIGS. 16A-16D include secondsolar cell 1614 with busbar 1616 disposed on backside surface 1610,insulating layer 1618 disposed on peripheral side surface 1617, and ECA1619 overlying at least a portion of insulating layer 1618 and busbar1616. Interconnection element 1601 interconnects the two solar cellsthrough respect ECA 1609/1619. FIG. 16A shows solar cells interconnectedusing an electrically conductive elastomer in which the electricallyconductive filler is homogenously dispersed throughout the elastomericinterconnection element 1601. FIG. 16B shows solar cells interconnectedusing an electrically conductive elastomer in which the electricallyconductive filler is disposed on the exterior surface of the elastomericinterconnection element. FIG. 16C shows an elastomeric interconnectionelement comprising an exterior electrically conductive thin-film 1602.FIG. 16D shows an elastomeric interconnection element 1601 comprising anelectrically conductive film 1602 in which the exposed exterior surfacesof the element comprise a weatherable material 1603.

Solar cell interconnects provided by the present disclosure includetandem backside interconnects. Tandem backside interconnects do not haveany busbars on the frontside surface of the solar cell and therebyincrease the irradiation area. In a tandem backside interconnect, thefrontside busbar overlies the backside surface of the solar cell, andthe frontside gridlines and/or frontside busbar extend over theperipheral side surface and is interconnected to the frontside busbaroverlying the backside surface.

An example of a tandem backside solar cell interconnect is shown in FIG.17A.

FIG. 17A shows solar cell 1700 including a substrate 1701, a frontsidesurface 1702, backside surface 1703, and peripheral side surface 1704. Aside surface insulating layer 1705 overlies the peripheral side surface1704. A frontside busbar 1707 is disposed on a frontside busbarinsulating layer 1706 overlying the backside surface 1703 in proximityto the peripheral side surface 1704. Frontside gridlines 1708 overlie aportion of the frontside surface 1702, overlie a portion of the sidesurface insulating layer 1705 and are interconnected to frontside busbar1707. A backside busbar 1709 is disposed on backside surface 1703 inproximity to second peripheral side surface 1710. Backside gridlines1711 extend across a portion of backside surface 1703 and areinterconnected to backside busbar 1709.

The backside insulating layer, which isolates the frontside busbar onthe backside of the sub-cell from the backside doped region (base) ofthe solar cell can be a portion of the backside insulating dielectricsurface used for protecting and passivating the backside of a solar cellsuch as a N-type PERT or P-type PERC solar cell. For Al-BSF solar cellswith no backside insulating layer, a printed insulating layer can beapplied to a portion of the backside surface solar cell in proximity tothe edge of the solar cell that that does not have an aluminumconductor.

A side view of a tandem backside interconnect is shown in FIG. 17B.

The side view of a tandem backside interconnect shown in FIG. 17Bincludes frontside surface 1702 and backside surface 1703. Backsideinsulating layer 1706 overlies at least a portion of the backsidesurface 1703 in proximity to the peripheral side surface. A side surfaceinsulating layer 1705 overlies the peripheral side surface. One or morefrontside busbars 1707 overlie the backside insulating layer 1706.Frontside gridlines 1708 disposed on the frontside surface 1702 extendover side surface insulating layer 1705 and over at least a portion of afrontside busbar 1707.

Backside insulating layers can extend the length of the solar cell orcan be disposed on portions of the backside surface in proximity to theside edge.

Materials used to form the gridlines, busbars, side surface insulatinglayers can be the same as described for the solar cells comprising theside-surface interconnects.

The frontside busbar insulating layer can comprise, for example, aninsulator-type elastomeric resist, a printed dielectric that forms aftercuring, or a dielectric already present on the backside of the solarcell such as a P-type PERC or N-type PERT solar cell.

Photovoltaic modules can comprise two or more solar cells comprising atandem backside interconnect provided by the present disclosure.

A photovoltaic module can be formed by positioning two solar cellscomprising a tandem backside interconnect in a planar, side-by-sideconfiguration and connecting the frontside busbar of a first solar cellto a backside busbar of a second solar cell using, for example, anelectrically conductive element such as an electrically conductiveribbon, wire, or tab. The electrically conductive element can be, forexample, soldered or welded to the busbars. The electrically conductiveelement can be flexible so as to accommodate shear stress during use.

In embodiments in which solar cells comprising a tandem backsideinterconnect comprise two or more frontside busbars and/or backsidebusbar segments, the two or more frontside busbar segments of a firstsolar cell can be independently connected to respective two or morebackside busbar segments of a second solar cell using an electricallyconductive element.

A side view of a photovoltaic module comprising two interconnected solarcells are shown in FIG. 18,

FIG. 18 shows a first subcell 1800 a and a second subcell 1800 bincluding substrates 1801 a/1801 b, frontside surfaces 1802 a/1802 b,backside surfaces 1803 a/1803 b, first peripheral side surfaces 1804a/1804 b, and peripheral side surface insulating layers 1805 a/1805 boverlying first peripheral side surfaces 1804 a/1804 b. Backsideinsulating layers 1806 a/1806 b overlie backside surfaces 1803 a/1803 bor portions of the backside surfaces 1803 a/1803 b and frontside busbar1807 a/1807 b overly the one or more backside surface insulating layers1806 a/1806 b. Frontside gridlines 1808 a/1808 b extend over peripheralside surface insulating layers 1805 a/1805 b and are interconnected tofrontside busbar 1807 a/1807 b. Backside busbar 1809 a/1809 b aredisposed on the backside surface 1803 a/1803 b in proximity to secondperipheral side surface 1810 a/1810 b. Backside gridlines 1811 a/1811 bare electrically interconnected to the backside busbar 1809 a/1809 b.Side surface insulating layers 1812 a/1812 b overlie second peripheralside surfaces 1810 a/1810 b.

The one or more frontside busbar segments 1807 a of the first subcellare interconnected to respective one or more backside busbars 1809 b ofthe second subcell by one or more electrically conductive elements suchas electrically conductive tabs 1814 to provide the tandem backsideinterconnect 1813.

In FIG. 18, the two solar cells are shown as being spaced apart with agap between the conductors 1808 a on the first solar cell and theinsulating layer 1812 b on the second solar cell. However, because theperipheral side surfaces of the solar cells are insulated, the opposingsurfaces of the adjacent solar cells may be close together or incontact, for example, such that conductors 1808 a contact insulatinglayer 1812 b. In this way, the active surface area of a photovoltaicsystem can be maximized and the interconnection resistance between solarcells minimized, thereby increasing the overall fill factor and theefficiency of a photovoltaic system formed using small area solar cellsinterconnected using tandem backside interconnects provided by thepresent disclosure.

Solar cells comprising tandem backside interconnects provided by thepresent disclosure can be fabricated using solar cell and semiconductormanufacturing methods known in the art.

A side surface insulating layer can be applied to at least oneperipheral side surface of a solar cell substrate. The side surfaceinsulating layer can be applied using additive manufacturing, thin-filmcoating, or by gas phase deposition such as be MOCVD.

The one or more frontside busbar segments insulating layers on thebackside can be a dielectric already pre-existing before cutting theoriginal large-area solar cell into sub-cells that has been deposited bya CVD process or the insulating layer can be applied using screenprinting.

Similarly, the electrically conductive element such as the frontsidebusbars, the backside busbars, the frontside busbars, and the backsidebusbars can be deposited by screen printing conductive pastes.

The frontside gridlines can be extended over the side surface insulatinglayer and interconnected to frontside busbars by screen printing or byadditive manufacturing such as three-dimensional printing or inkjetprinting.

For example, after the frontside gridlines and the frontside busbars arefabricated, or in embodiments where the frontside gridlines and/orbusbars are present on the small area solar cells after they have beencut from a large area solar cell, extensions of the frontside gridlinescan be deposited onto the side surface insulating layer bythree-dimensional printing. The gridline extensions wrapping around aperipheral side surface to the backside comprise an electricallyconductive adhesive material cured at low temperature, such as at atemperature from 150° C. to 250° C.

Alternatively, after the side surface insulating layer is deposited ontoa side surface of the solar cell substrate, a copper conductor can bedeposited onto the insulating layer to extend the gridlines.

Solar cells provided by the present disclosure can be incorporated intophotovoltaic modules, and the photovoltaic modules can be incorporatedinto power generation systems. Thus, aspects of the invention includephotovoltaic modules and power generation systems comprising solar celledge interconnects provided by the present disclosure.

Photovoltaic modules interconnected using the edge interconnectsprovided by the present disclosure can maintain acceptable conductivityand adhesion strength following exposure to accelerated environmentaltest conditions including damp-heat testing and accelerated thermalcycling, which are used to qualify solar cells for a 25-year servicelife.

The use of solar cell edge interconnects provided by the presentdisclosure can facilitate the use of small-area solar cells. It isestimated that the output of a photovoltaic module interconnected usingthe disclosed methods will have approximately 2% improvement in absolutemodule efficiency compared to a photovoltaic module interconnected usingtraditional front-to-back ribbons and about 0.3% absolute moduleefficiency improvement over shingled solar cell designs for a bifacialphotovoltaic module.

ASPECTS OF THE INVENTION

The invention is further defined by the following aspects.

Aspect 1

A solar cell, wherein the solar cell comprises: a surface and aperipheral side surface; a busbar, wherein the busbar is in proximity tothe peripheral side surface; an insulating layer overlying theperipheral side surface; and an electrically conductive adhesiveoverlying at least a portion of the insulating layer and overlying atleast a portion of the busbar.

Aspect 2

The solar cell of aspect 1, wherein the electrically conductive adhesivecomprises Ag, Cu, or a combination thereof.

Aspect 3

The solar cell of any one of aspects 1 to 2, wherein the insulatinglayer comprises a dielectric layer comprising SiO₂, Si₃N₄, or Al₂O₃.

Aspect 4

The solar cell of any one of aspects 1 to 2, wherein the insulatinglayer comprises a copper diffusion barrier dielectric material.

Aspect 5

The solar cell of aspect 4, wherein the copper diffusion barrierdielectric material comprises titanium silicon nitride, silicon nitride,ZrB₂, MnSi_(x)O_(y), or a combination of any of the foregoing.

Aspect 6

The solar cell of any one of aspects 1 to 5, wherein the insulatinglayer is configured to passivate the peripheral side surface of thesolar cell.

Aspect 7

The solar cell of any one of aspects 1 to 6, wherein the solar cellcomprises a silicon substrate.

Aspect 8

The solar cell of any one of aspects 1 to 7, further comprising a solderpaste overlying at least a portion of the electrically conductiveadhesive.

Aspect 9

The solar cell of aspect 8, wherein the solder paste comprises Sn; andAg, Cu, Pb, Bi, or a combination of any of the foregoing.

Aspect 10

A photovoltaic module, comprising: a first solar cell of any one ofaspects 1 to 9, wherein the first solar cell comprises a firstelectrically conductive adhesive; a second solar cell of any one ofaspects 1 to 9, wherein the second solar cell comprises a secondelectrically conductive adhesive; and an interconnection elementinterconnecting the first electrically conductive adhesive and thesecond electrically conductive adhesive.

Aspect 11

The photovoltaic module of aspect 10, wherein the interconnectionelement comprises a solder paste.

Aspect 12

The photovoltaic module of aspect 11, wherein the solder paste comprisesSn; and Ag, Cu, Pb, Bi, or a combination of any of the foregoing.

Aspect 13

The solar cell module of any one of aspects 10 to 12, wherein theinterconnection element comprises a solder-coated ribbon.

Aspect 14

The photovoltaic module of aspect 13, wherein the outer surfaces of thesolder-coated ribbon are rounded, textured, or a combination thereof.

Aspect 15

The photovoltaic module of any one of aspects 13 to 14, wherein thesolder-coated ribbon has a round cross-sectional profile or an ovalcross-sectional profile.

Aspect 16

The photovoltaic module of any one of aspects 13 to 15, wherein thesolder-coated ribbon comprises a solder-coated copper foil.

Aspect 17

The method of any one of aspects 10 to 16, wherein the interconnectionelement comprises an elastomeric interconnection element.

Aspect 18

The photovoltaic module of any one of aspects 13 to 17, wherein thesolder-coated ribbon comprises a coating of Sn; and Ag, Cu, Pb, or acombination of any of the foregoing.

Aspect 19

The photovoltaic module of any one of aspects 10 to 18, wherein theinterconnection element has a width less than 250 μm.

Aspect 20

The photovoltaic module of any one of aspects 10 to 18, wherein theinterconnection element has a width from 50 μm to 250 μm.

Aspect 21

The photovoltaic module of any one of aspects 10 to 20, wherein theinterconnection element has a thickness within ±10% the thickness of thesolar cell.

Aspect 22

The photovoltaic module of any one of aspects 10 to 21, wherein theinterconnection element has a thickness less than 200 μm.

Aspect 23

The photovoltaic module of any one of aspects 10 to 21, wherein theinterconnection element has a thickness from 50 μm to 200 μm.

Aspect 24

The photovoltaic module of any one of aspects 10 to 23, wherein thefirst solar cell and the second solar cell are coplanar.

Aspect 25

The photovoltaic module of any one of aspects 10 to 24, wherein a busbaron the frontside of the first solar cell is electrically interconnectedto a busbar on the backside of the second solar cell.

Aspect 26

A photovoltaic module comprising at least two solar cells of any one ofaspects 1 to 9.

Aspect 27

A power system comprising a plurality of the photovoltaic modules ofaspect 26.

Aspect 28

A method of fabricating a solar cell peripheral side surfaceinterconnect, comprising: depositing an insulating layer overlying aperipheral side surface of a solar cell; depositing a busbarmetallization in proximity to the peripheral side surface of the solarcell; and depositing an electrically conductive adhesive overlying atleast a portion of the insulating layer and overlying at least a portionof the busbar to provide a solar cell peripheral side surfaceinterconnect.

Aspect 29

The method of aspect 28, further comprising, after depositing the busbarmetallization, curing the busbar metallization to form a busbar.

Aspect 30

The method of any one of aspects 28 to 29, further comprising, afterdepositing the electrically conductive adhesive, curing the electricallyconductive adhesive.

Aspect 31

The method of aspect 30, further comprising, after curing theelectrically conductive adhesive, depositing a solder paste overlying atleast a portion of the cured electrically conductive adhesive.

Aspect 32

The method of aspect 31, wherein depositing the solder paste comprisesadditive manufacturing.

Aspect 33

The method of any one of aspects 28 to 32, further comprising, afterdepositing the insulating layer, depositing the busbar in proximity tothe peripheral side surface of a solar cell.

Aspect 34

The method of aspect 32, wherein depositing the busbar comprises screenprinting a metallization paste.

Aspect 35

The method of any one of aspects 28 to 34, wherein depositing theinsulating layer comprises chemical vapor deposition.

Aspect 36

The method of any one of aspects 28 to 34, wherein depositing theelectrically conductive adhesive comprises additive manufacturing.

Aspect 37

A solar cell comprising an interconnect fabricated using the method ofany one of aspects 28 to 36.

Aspect 38

A photovoltaic module comprising at least two solar cells of aspect 37.

Aspect 39

A power system comprising a plurality of the photovoltaic modules ofaspect 38.

Aspect 40

A method of interconnecting solar cells, comprising: contacting a firstelectrically conductive adhesive of a first solar cell of any one ofaspects 1 to 9 and a second electrically conductive adhesive of a secondsolar cell of any one of aspects 1 to 9 with an interconnection element;and bonding the interconnection element to the first and secondelectrically conductive adhesives to electrically interconnect the firstsolar cell and the second solar cell.

Aspect 41

The method of aspect 40, wherein the interconnection element comprises asolder paste.

Aspect 42

The method of any one of aspects 40 to 41, wherein the interconnectionelement comprises a solder-coated ribbon.

Aspect 43

The method of aspect 42, wherein outer surfaces of the solder-coatedribbon are rounded, textured, or a combination thereof.

Aspect 44

The method of any one of aspects 42 to 43, wherein the solder-coatedribbon has a round cross-sectional profile or an oval cross-sectionalprofile.

Aspect 45

The method of any one of aspects 42 to 44, wherein the solder-coatedribbon comprises a solder-coated Cu foil.

Aspect 46

The method of any one of aspects 42 to 45, wherein the solder-coatedribbon comprises a coating of Sn; and Ag, Cu, Pb, Bi or a combination ofany of the foregoing.

Aspect 47

The method of any one of aspects 40 to 46, wherein the interconnectionelement has a width less than 250 μm.

Aspect 48

The method of any one of aspects 40 to 46, wherein the interconnectionelement has a width from 50 μm to 250 μm.

Aspect 49

The method of any one of aspects 40 to 48, wherein the interconnectionelement has a thickness that is less than ±10% the thickness of thesolar cell.

Aspect 50

The method of any one of aspects 40 to 49, wherein the interconnectionelement has a thickness less than 200 μm.

Aspect 51

The method of any one of aspects 40 to 49, wherein the interconnectionelement has a thickness from 50 μm to 200 μm.

Aspect 52

The method of any one of aspects 40 to 50, wherein the interconnectionelement comprises an elastomeric interconnection element.

Aspect 53

The method of aspect 52, wherein the elastomeric interconnection elementcomprises an electrically conductive elastomer.

Aspect 54

The method of any one of aspects 52 to 53, wherein at least a portion ofthe exterior surface of the elastomeric interconnection element iselectrically conductive.

Aspect 55

The method of any one of aspects 52 to 54, wherein at least a portion ofthe interior of the elastomeric interconnection element is electricallyconductive.

Aspect 56

The method of any one of aspects 40 to 55, wherein the method furthercomprises depositing the interconnection element between the first solarcell and the second solar cell.

Aspect 57

The method of aspect 56, wherein depositing the interconnection elementcomprises depositing using additive manufacturing.

Aspect 58

The method of any one of aspects 40 to 57, wherein contacting comprises:bringing the first electrically conductive adhesive in proximity to thesecond electrically conductive adhesive; and depositing aninterconnection element to contact both the first electricallyconductive adhesive in proximity to the second electrically conductiveadhesive.

Aspect 59

The method of aspect of any one of 40 to 58, wherein the interconnectionelement comprises a solder paste.

Aspect 60

The method of any one of aspects 40 to 58, wherein the interconnectionelement comprises an electrically conductive elastomer.

Aspect 61

The method of any one of aspects 40 to 58, wherein the interconnectionelement comprises an electrically conductive elastomeric element.

Aspect 62

The method of any one of aspects 40 to 61, wherein the first solar cellfurther comprises a solder paste overlying at least a portion of thefirst electrically conductive adhesive; and contacting comprisesbringing the solder paste into contact with the second electricallyconductive adhesive.

Aspect 63

The method of any one of aspects 40 to 61, wherein, the first solar cellfurther comprises a first solder paste overlying at least a portion ofthe first electrically conductive adhesive; the second solar cellfurther comprises a second solder paste overlying at least a portion ofthe second electrically conductive adhesive; and contacting comprisescontacting the first solder paste to the second solder paste.

Aspect 64

Solar cells interconnected using the method of any one of aspects 40 to63.

Aspect 65

A photovoltaic module comprising the solar cells of aspect 64.

Aspect 66

A power system comprising a plurality of the photovoltaic modules ofaspect 65.

Aspect 1A

A solar cell, wherein the solar cell comprises: a substrate, wherein thesubstrate comprises a surface and a first peripheral side surface; oneor more busbar segments disposed on the surface and in proximity to thefirst peripheral side surface; an insulating layer overlying at least aportion of the first peripheral side surface; and an electricallyconductive adhesive overlying at least a portion of the insulating layerand overlying at least a portion of each of the one or more busbarsegments.

Aspect 2A

The solar cell of aspect 1A, wherein the surface comprises a frontsidesurface and the one or more busbar segments comprise one or morefrontside busbar segments.

Aspect 3A

The solar cell of any one of aspects 1A to 2A, wherein the surfacecomprises a backside surface and the one or more busbar segmentscomprise one or more backside busbar segments.

Aspect 4A

The solar cell of any one of aspects 1A to 3A, wherein the substratecomprises a silicon substrate.

Aspect 5A

The solar cell of any one of aspects 1A to 4A, wherein the one or morebusbar segments comprises two or more busbar segments.

Aspect 6A

The solar cell of any one of aspects 1A to 5A, further comprising aplurality of gridlines disposed on the surface, wherein each of theplurality of gridlines is interconnected to a busbar segment.

Aspect 7A

The solar cell of any one of aspects 1A to 6A, wherein the insulatinglayer overlies the entire first peripheral side surface.

Aspect 8A

The solar cell of any one of aspects 1A to 6A, wherein the electricallyconductive adhesive overlies a substantial portion of the firstperipheral side surface.

Aspect 9A

The solar cell of any one of aspects 1A to 8A, wherein the one or morebusbar segments comprise a single busbar segment disposed on the surfaceand in proximity to the first peripheral side surface.

Aspect 10A

The solar cell of aspect 9A, wherein the single busbar segment spans asubstantial length of the surface.

Aspect 11A

The solar cell of any one of aspects 9A to 10A, further comprising aplurality of gridlines disposed on the surface, wherein each of theplurality of gridlines is interconnected to a busbar segment.

Aspect 12A

The solar cell of any one of aspects 1A to 11A, wherein the firstperipheral side surface comprises: two or more first portions, whereineach of the two or more first portions are commensurate with the one ormore busbar segments; and one or more second portions, wherein each ofthe one or more second portions is adjacent a first portion or betweentwo first portions.

Aspect 13A

The solar cell of aspect 12A, wherein the electrically conductiveadhesive overlies each of the two or more first portions and overlies abusbar segment.

Aspect 14A

The solar cell of any one of aspects 12A to 13A, further comprising anelastomeric element overlying each of the second portions.

Aspect 15A

The solar cell of any one of aspects 12A to 13A, further comprising anelastomeric element overlying at least one of the second portions.

Aspect 16A

The solar cell of any one of aspects 1A to 15A, wherein the insulatinglayer comprises a dielectric material.

Aspect 17A

The solar cell of any one of aspects 1A to 16A, wherein the insulatinglayer has a thickness from 10 nm to 100 nm.

Aspect 18A

The solar cell of any one of aspects 1A to 17A, wherein the electricallyconductive adhesive has a thickness from 3 μm to 100 μm.

Aspect 19A

The solar cell of any one of aspects 1A to 18A, wherein the electricallyconductive adhesive comprises a blocked polyisocyanate prepolymer.

Aspect 20A

The solar cell of any one of aspects 1A to 19A, wherein the electricallyconductive adhesive comprises a polyepoxide.

Aspect 21A

The solar cell of any one of aspects 1A to 20A, wherein the solar cellhas a surface area less than 10,000 mm².

Aspect 22A

The solar cell of any one of aspects 1A to 20A, wherein the solar cellhas a surface area from 500 mm² to 6,000 mm².

Aspect 23A

The solar cell of any one of aspects 1A to 22A, wherein the solar cellcomprises a backside surface and the backside surface comprise anelectrically conductive layer.

Aspect 24A

The solar cell of any one of aspects 1A to 22A, wherein, the surfacecomprises a frontside surface; the one or more busbar segments compriseone or more frontside busbar segments; and the solar cell furthercomprises: a backside surface and a second peripheral side surface; andone or more backside busbar segments disposed on the backside surface inproximity to the second peripheral side surface.

Aspect 25A

The solar cell of aspect 24A, further comprising a plurality of backsidegridlines disposed on the backside surface and interconnected to the oneor more backside busbar segments.

Aspect 26A

The solar cell of any one of aspects 24A to 25A, wherein, the firstperipheral side surface comprises one or more first portions and one ormore second portions; the one or more first portions are commensuratewith one of the one or more busbar segments; and the electricallyconductive adhesive is disposed on each of the one or more firstportions.

Aspect 27A

The solar cell of any one of aspects 24A to 26A, further comprising: oneor more second portions, wherein each of the one or more second portionsis adjacent a first portion or between two first portions; and anelastomeric element disposed on at least one of the second portions.

Aspect 28A

The solar cell of any one of aspects 24A to 26A, further comprising: oneor more second portions, wherein each of the one or more second portionsis adjacent a first portion or between two first portions; and anelastomeric element disposed on each of the second portions.

Aspect 29A

The solar cell of any one of aspects 24A to 28A, wherein, the secondperipheral side surface comprises one or more first portions and one ormore second portions; the one or more first portions are in proximity toeach of the one or more busbar segments; and the electrically conductiveadhesive is disposed on each of the one or more first portions.

Aspect 30A

The solar cell of aspect 29A, further comprising an elastomeric elementdisposed on at least one of the second portions.

Aspect 31A

The solar cell of aspect 29A, further comprising an elastomeric elementdisposed on each of the second portions.

Aspect 32A

A photovoltaic module, comprising: a first solar cell of any one ofaspects 24A to 31A comprising one or more first frontside busbarsegments and a first electrically conductive adhesive; and a secondsolar cell of any one of aspects 24A to 31A comprising one or moresecond backside busbar segments and a second electrically conductiveadhesive; wherein the first electrically conductive adhesive and thesecond electrically conductive adhesive are bonded and electricallyinterconnect the one or more first frontside busbar segments to the oneor more second backside busbar segments.

Aspect 33A

A photovoltaic module, comprising: a first solar cell, wherein the firstsolar cell comprises a first frontside surface, a first backsidesurface, a first peripheral side surface, one or more frontside busbarsegments disposed on the first frontside surface and in proximity to thefirst peripheral side surface, and a first insulating layer overlyingthe first peripheral side surface; a second solar cell, wherein thesecond solar cell comprises a second frontside surface, a secondbackside surface, a second peripheral side surface, one or more backsidebusbar segments disposed on the second backside surface and in proximityto the second peripheral side surface, and a second insulating layeroverlying the second peripheral side surface; and an electricallyconductive adhesive disposed on the first insulating layer and on thesecond insulating layer and overlying at least a portion of the one ormore first frontside busbar segments and overlying at least a portion ofthe one or more backside busbar segments.

Aspect 34A

The photovoltaic module of aspect 33A, wherein, the first solar cellfurther comprises a plurality of first frontside gridlines disposed onthe first surface and interconnected to the one or more frontside busbarsegments; and the second solar cell further comprises a plurality ofbackside gridlines disposed on the second backside surface andinterconnected to the one or more backside busbar segments.

Aspect 35A

The photovoltaic module of any one of aspects 33A to 34A, wherein theelectrically conductive adhesive on the first peripheral side surfaceand the second peripheral side surface has a thickness from 5 μm to 200μm.

Aspect 36A

The photovoltaic module of any one of aspects 33A to 35A, furthercomprising a mechanical support element overlying the electricallyconductive adhesive disposed between the first solar cell and the secondsolar cell.

Aspect 37A

The photovoltaic module of any one of aspects 33A to 36A, wherein theelectrically conductive adhesive spans the length of the firstperipheral side surface and the length of the second peripheral sidesurface.

Aspect 38A

The photovoltaic module of any one of aspects 33A to 36A, wherein, thefirst peripheral side surface comprises one or more first portionswherein each of the one or more first portions is in proximity to eachof the one or more frontside busbar segments, and the first peripheralside surface comprises one or more second portions wherein each of theone or more second portions adjoins one or more of the first portions;the second peripheral side surface comprises one or more first portionswherein each of the one or more first portions is in proximity to eachof the one or more backside busbar segments, and the second peripheralside surface comprises one or more second portions wherein each of theone or more second portions adjoins one or more of the first portions;and the electrically conductive adhesive is bonded to and interconnectseach of the one or more first portions of the first peripheral sidesurface to a respective one or more first portions of the secondperipheral side surface.

Aspect 39A

The photovoltaic module of aspect 38A, further comprising an elastomericelement bonded to at least one of the one or more second portions of thefirst solar cell and to a respective one of the one or more secondportions of the second solar cell.

Aspect 40A

The photovoltaic module of any one of aspects 38A to 39A, wherein thefirst solar cell and the second solar cell are coplanar.

Aspect 41A

A photovoltaic system comprising two or more photovoltaic modules of anyone of aspects 32A to 40A.

Aspect 42A

A method of fabricating a solar cell interconnect, comprising:depositing an insulating layer overlying a peripheral side surface of asolar cell; and depositing an electrically conductive adhesive overlyingat least a portion of the insulating layer and overlying at least aportion of each of one or more busbar segments to provide a solar cellinterconnect.

Aspect 43A

The method of aspect 42A, further comprising, before depositing theinsulating layer, cutting a large area solar cell to provide a pluralityof small area solar cells, and the solar cell comprises a small areasolar cell.

Aspect 44A

The method of any one of aspects 42A to 43A, wherein the small areasolar cell has an area from 600 mm² to 10,000 mm².

Aspect 45A

The method of any one of aspects 42A to 44A, wherein depositing theinsulating layer comprises additive manufacturing.

Aspect 46A

The method of any one of aspects 42A to 44A, wherein depositing theinsulating layer comprises chemical vapor deposition.

Aspect 47A

The method of any one of aspects 42A to 46A, wherein depositing theelectrically conductive adhesive comprises additive manufacturing.

Aspect 48A

A solar cell comprising an interconnect fabricated using the method ofany one of aspects 42A to 47A.

Aspect 49A

A method of interconnecting solar cells, comprising: contacting a firstelectrically conductive adhesive of a first solar cell of any one ofaspects 1A to 31A to a second electrically conductive adhesive of asecond solar cell of any one of aspects 1A to 31A; and bonding the firstelectrically conductive adhesive to the second electrically conductiveadhesive to interconnect the first solar cell and the second solar cell.

Aspect 50A

The method of aspect 49A, wherein, the first solar cell comprises one ormore frontside busbar segments; the second solar cell comprises one ormore backside busbar segments; and after bonding, the electricallyconductive adhesive interconnects the one or more frontside busbarsegments to the one or more backside busbar segments.

Aspect 51A

The method of any one of aspects 49A to 50A, wherein contactingcomprises contacting a wet first electrically conductive adhesive to awet second electrically conductive adhesive.

Aspect 52A

The method of aspect 51A, wherein bonding comprises curing the wet firstelectrically conductive adhesive and the wet second electricallyconductive adhesive.

Aspect 53A

The method of aspect 52A, wherein curing comprises exposing the firstwet electrically conductive adhesive and the second wet electricallyconductive adhesive to a temperature from 150° C. to 250° C. for aduration from 20 minutes to 60 minutes.

Aspect 54A

The method of any one of aspects 52A to 53A, further comprising, priorto curing, drying the first wet electrically conductive adhesive anddrying the second wet electrically conductive adhesive.

Aspect 55A

The method of aspect 54A, wherein drying comprises exposing the firstwet electrically conductive adhesive and the second wet electricallyconductive adhesive to a temperature from 100° C. to 200° C. for aduration from 5 minutes to 20 minutes.

Aspect 56A

Solar cells interconnected using the method of any one of aspects 49A to55A.

Aspect 57A

A photovoltaic module comprising the solar cells of aspect 56A.

Aspect 58A

A power system comprising a plurality of the photovoltaic modules ofaspect 57A.

Aspect 59A

A solar cell comprising: a substrate comprising a frontside surface, abackside surface, a first peripheral side surface, and a secondperipheral side surface; a side surface insulating layer overlying thefirst peripheral side surface; a backside insulating layer overlying aportion of the backside surface in proximity to the first peripheralside surface; one or more frontside busbar segments overlying thebackside insulating layer; and a plurality of frontside gridlinesdisposed on the frontside surface and interconnected to the one or morefrontside busbar segments.

Aspect 60A

The solar cell of aspect 59A, wherein each of the plurality of frontsidegridlines is disposed on the side surface insulating layer and isinterconnected to the one or more frontside busbar segments.

Aspect 61A

The solar cell of any one of aspects 59A to 60A, wherein, each of theone or more frontside busbar segments is disposed on the firstperipheral side surface; and each of the plurality of frontsidegridlines is interconnected to the one or more frontside busbarsegments.

Aspect 62A

The solar cell of any one of aspects 59A to 60A, further comprising: oneor more backside busbar segments disposed on the backside surface inproximity to the second peripheral side surface; and a plurality ofbackside gridlines disposed on the backside surface and interconnectedto the one or more backside busbar segments.

Aspect 63A

A photovoltaic module, comprising: a first solar cell of any one ofaspects 59A to 62; a second solar cell of any one of aspects 59A to 62A;an interconnection element interconnecting the one or more frontsidebusbar segments of the first solar cell to the one or more backsidebusbar segments of the second solar cell.

Aspect 64A

The photovoltaic module of aspect 63A, wherein the interconnectionelement comprises a conductive tab.

Aspect 65A

A power system comprising a plurality of the photovoltaic modules ofaspect 64A.

Aspect 66A

A method of fabricating a solar cell interconnect comprising: applyingan insulating layer to a peripheral side surface of a solar cell; andextending gridlines on a frontside surface of the solar cell over theinsulating layer and onto one or more busbar segments on a backsidesurface of the solar cell.

Aspect 67A

The method of aspect 66A, wherein extending the gridlines comprisesdepositing an electrically conductive adhesive on the insulating layerand interconnecting the gridlines and the one or more busbar segments.

Aspect 68A

A solar cell comprising an interconnect made by the method of any one ofaspects 66A to 67A.

Aspect 69A

A solar cell module comprising a first solar cell of aspect 68Ainterconnected to a second solar cell of aspect 68A

Finally, it should be noted that there are alternative ways ofimplementing the embodiments disclosed herein. Accordingly, the presentembodiments are to be considered as illustrative and not restrictive.Furthermore, the claims are not to be limited to the details givenherein and are entitled to their full scope and equivalents thereof.

What is claimed is:
 1. A solar cell, wherein the solar cell comprises: asubstrate, wherein the substrate comprises a surface and a firstperipheral side surface; one or more busbar segments disposed on thesurface and in proximity to the first peripheral side surface; aninsulating layer overlying at least a portion of the first peripheralside surface; and an electrically conductive adhesive overlying at leasta portion of the insulating layer and overlying at least a portion ofeach of the one or more busbar segments.
 2. The solar cell of claim 1,wherein the surface comprises a frontside surface and the one or morebusbar segments comprise one or more frontside busbar segments.
 3. Thesolar cell of claim 1, further comprising a plurality of gridlinesdisposed on the surface, wherein each of the plurality of gridlines isinterconnected to a busbar segment.
 4. The solar cell of claim 1,wherein the first peripheral side surface comprises: two or more firstportions, wherein each of the two or more first portions arecommensurate with the one or more busbar segments; and one or moresecond portions, wherein each of the one or more second portions isadjacent a first portion or between two first portions.
 5. The solarcell of claim 4, wherein the electrically conductive adhesive overlieseach of the two or more first portions and overlies a busbar segment. 6.The solar cell of claim 4, further comprising an elastomeric elementoverlying at least one of the second portions.
 7. The solar cell ofclaim 1, wherein the solar cell has a surface area less than 10,000 mm².8. The solar cell of claim 1, wherein, the surface comprises a frontsidesurface; the one or more busbar segments comprise one or more frontsidebusbar segments; and the solar cell further comprises: a backsidesurface and a second peripheral side surface; and one or more backsidebusbar segments disposed on the backside surface in proximity to thesecond peripheral side surface.
 9. A photovoltaic module, comprising: afirst solar cell claim 8 comprising one or more first frontside busbarsegments and a first electrically conductive adhesive; and a secondsolar cell of claim 8 comprising one or more second backside busbarsegments and a second electrically conductive adhesive; wherein thefirst electrically conductive adhesive and the second electricallyconductive adhesive are bonded and electrically interconnect the one ormore first frontside busbar segments to the one or more second backsidebusbar segments.
 10. A photovoltaic system comprising two or morephotovoltaic modules of claim
 9. 11. A photovoltaic module, comprising:a first solar cell, wherein the first solar cell comprises a firstfrontside surface, a first backside surface, a first peripheral sidesurface, one or more frontside busbar segments disposed on the firstfrontside surface and in proximity to the first peripheral side surface,and a first insulating layer overlying the first peripheral sidesurface; a second solar cell, wherein the second solar cell comprises asecond frontside surface, a second backside surface, a second peripheralside surface, one or more backside busbar segments disposed on thesecond backside surface and in proximity to the second peripheral sidesurface, and a second insulating layer overlying the second peripheralside surface; and an electrically conductive adhesive disposed on thefirst insulating layer and on the second insulating layer and overlyingat least a portion of the one or more first frontside busbar segmentsand overlying at least a portion of the one or more backside busbarsegments.
 12. The photovoltaic module of claim 11, wherein, the firstsolar cell further comprises a plurality of first frontside gridlinesdisposed on the first surface and interconnected to the one or morefrontside busbar segments; and the second solar cell further comprises aplurality of backside gridlines disposed on the second backside surfaceand interconnected to the one or more backside busbar segments.
 13. Thephotovoltaic module of claim 11, wherein, the first peripheral sidesurface comprises one or more first portions wherein each of the one ormore first portions is in proximity to each of the one or more frontsidebusbar segments, and the first peripheral side surface comprises one ormore second portions wherein each of the one or more second portionsadjoins one or more of the first portions; the second peripheral sidesurface comprises one or more first portions wherein each of the one ormore first portions is in proximity to each of the one or more backsidebusbar segments, and the second peripheral side surface comprises one ormore second portions wherein each of the one or more second portionsadjoins one or more of the first portions; and the electricallyconductive adhesive is bonded to and interconnects each of the one ormore first portions of the first peripheral side surface to a respectiveone or more first portions of the second peripheral side surface. 14.The photovoltaic module of claim 13, further comprising an elastomericelement bonded to at least one of the one or more second portions of thefirst solar cell and to a respective one of the one or more secondportions of the second solar cell.
 15. A photovoltaic system comprisingtwo or more photovoltaic modules of claim
 11. 16. A method ofinterconnecting solar cells, comprising: contacting a first electricallyconductive adhesive of a first solar cell of claim 1 to a secondelectrically conductive adhesive of a second solar cell of claim 2; andbonding the first electrically conductive adhesive to the secondelectrically conductive adhesive to interconnect the first solar celland the second solar cell.
 17. Solar cells interconnected using themethod of claim
 16. 18. A photovoltaic module comprising the solar cellsof claim
 17. 19. A power system comprising a plurality of thephotovoltaic modules of claim 18.